•6 On a new ftihn'tnat'ing M^ycuryi 



niable and carbonic acid gas, i ecn the mixed pfoduiSl ex-» 

 tricated from it by dilute fulphuric acid. 

 ; It however appears to me, that nitrous gas was really pro- 

 duced by the action of the dilute lalphuric acid ; and that, 

 when produced, it united to an cxcefs of oxygen prefent in 

 the oxalat of mercury. 



To explain how this change might happen, I muft pre- 

 jnife, that my experiments have fliown me, that oxalat of 

 mercury can exift in two, if not in three ftates. 



ift, By the difcovery of Mr. Ameilon already quoted, the 

 precipitate obtained by oxalic acid, from nitrat of mercury, 

 fufes with a hiffing iioife. This precipitate is an oxalat of 

 mercury, feemingly with excels of oxygen. Mercury dif- 

 folved in fulphuric acid and precipitated by oxalic acid, and 

 alfo the pure red oxyd of mercury digefted with oxalic acid, 

 give oxalats in the fame fiate. 



adly, Acetat of mercury precipitated by oxalic acid, aU 

 though a true oxalat is formed, has no kind of inflamma- 

 bility. I confider it as an oxalat with lefs oxygen than thofe 

 above mentioned. 



3dly, A folution of nitrat of mercury boiled with dulcified 

 fpirit of nitre, gives an oxalat more inflammable than any 

 other : perhaps it contains mofl: oxygen. 



The oxalat of mercury remaining from the powder in the 

 fulphuric liquor, is not only always in the fame ftate as that 

 precipitated from acetat of mercury, entirely devoid of in- 

 flammability, but contains globules of quickfilver ; confe- 

 quently, it muft have parted with even more than its excefs 

 of oxygen ; and, if nttrous gas was prefent, it would of courfe 

 •feize at leaft a portion of that oxygen. It is true, that glo- 

 bules of quickfilver may feem incompatible with nitrous 

 acid ; but the quantity of the one may not correfpond with 

 that of the other, or the dilution of the acid may deftroy its 

 action. 



As to the prefence of the carbonic acid, it muft have arifen 

 cither from a complete* decompofition of a part of the oxa- 



* Inflammable oxalat of mercury, made to fufe in a retort conn^fted 

 with the quickfil-er tub, givesout carbonic acid gas. 



